Many college students aren’t working very hard or learning very much, according to recent studies, writes New York Times columnist David Brooks, who suggests value-added assessments to show how much graduates have gained.

At some point, parents are going to decide that $160,000 is too high a price if all you get is an empty credential and a fancy car-window sticker.

. . . Colleges and universities have to be able to provide prospective parents with data that will give them some sense of how much their students learn.

Some schools like Bowling Green and Portland State are doing portfolio assessments — which measure the quality of student papers and improvement over time. Some, like Worcester Polytechnic Institute and Southern Illinois University Edwardsville, use capstone assessment, creating a culminating project in which the students display their skills in a way that can be compared and measured.

Colleges could pick an assessment method that “suits their vision,” writes Brooks.

Then they could broadcast the results to prospective parents, saying, “We may not be prestigious or as expensive as X, but here students actually learn.”

. . . If you’ve got a student at or applying to college, ask the administrators these questions: “How much do students here learn? How do you know?”

With many different learning assessment schemes, it would be difficult to compare schools — or to add a do-they-learn metric to the all-powerful U.S. News college rankings.